Prince Andrew just committed a hilarious mistake when he greeted Princess Beatrice on her 31st birthday.

On Twitter, the dad of two uploaded four photos supposedly of the birthday girl with their family. One of the throwback snaps was quite nostalgic for the Yorks since it also featured Sarah Ferguson. Prince Andrew and Fergie have been divorced for over two decades.

Another photo shows Prince Andrew with Princess Beatrice, who is riding her horse. The adorable young girl is looking into her dad’s eyes.

But two of the photos that Prince Andrew uploaded caught the attention of thousands of Twitter users. Instead of uploading pictures of Princess Beatrice, two photos featured Princess Eugenie.

One of the snaps was taken on Oct. 12, 2018, at Princess Eugenie and Jack Brooksbank’s royal wedding. Shortly after the greeting was uploaded, royal fans flocked to Prince Andrew’s account to make fun of his gaffe.

“Emmm this is a bit wee awkward?!?!” one person wrote.

“I never know who is Eugenie and who is Beatrice – thank God I’m not alone and their dad has the same problem,” another person commented.

Shortly after committing the blunder, the post was taken down and replaced with four new photos of Princess Beatrice.

In the new collage, the first photo features a young Princess Beatrice being carried by Ferguson at her christening. Prince Andrew is also in the photo. The second snap shows the 31-year-old holding hands with the Duke of York while she was in her pre-teen days.

The third and fourth pictures are of Princess Beatrice as a beautiful young lady. The third snap features her with Prince Andrew and the fourth snap shows her with Ferguson at Princess Eugenie’s wedding.

Meanwhile, the Duchess of York also greeted her eldest daughter via her Twitter account. Princess Eugenie also uploaded a touching tribute for her older sister on Instagram.

And a photo of Princess Beatrice was also uploaded via the Royal Family’s official Twitter account.

Prince Andrew, Sarah Ferguson and Princess Beatrice
Pictured: Prince Andrew, Ferguson and Princess Beatrice attend of the wedding of Princess Eugenie of York and Mr. Jack Brooksbank at St. George's Chapel on Oct. 12, 2018 in Windsor, England. Getty Images/Danny Lawson